Natural Selection in the Genus Cereus Mill. (Cactaceae; Cereeae): A Genomic Mapping Approach with Low-Coverage Sequencing

• Grant number: 24/23123-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2025
• End date: April 30, 2027
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Fernando de Faria Franco
• Grantee: Matheus Vieira da Silva
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

Understanding the adaptation process is fundamental in evolutionary biology. The project applies statistical approaches to identify signatures of natural selection in species of the family Cactaceae, specifically within the genus Cereus Mill., which is widely distributed across the Neotropical region. Biogeographical reconstructions suggest that niche evolution is partially associated with biogeographic transitions, indicating a significant role of natural selection in the diversification processes of the genus. The main objective of this study is to identify signatures of natural selection in specific clades of Cereus, focusing on metabolic genes that may elucidate the processes of biome colonization and diversification within the genus. To achieve this, a low-coverage genome sequencing data representing target clades of Cereus will be utilized, enabling the assembly of partial nuclear genomes and plastomes, annotation of coding and non-coding regions, identification of annotated genes, tests for natural selection based on evolutionary rate acceleration in non-coding regions, the ratio of nonsynonymous to synonymous substitution rates (dN/dS) for coding regions, and functional annotation of genes under positive selection.